Our understanding of periodontal disease progression has evolved from a generalized slowly progressive loss of attachment to one of recurrent, site-specific episodes of disease activity. Thus, the formulation of new approaches in periodontal therapy are predicated upon the ability to predict or detect whether a specific site will experience periodontal breakdown. The Forsyth Dental Center has correlated a set of clinical, host response and microbiologic risk factors with the subsequent loss of periodontal attachment in a largely non-minority, White population. While it is unknown whether risk factors associated with attachment loss in non- minority populations are similar to risk factors for destructive periodontal diseases in minority populations, recent studies suggest periodontal diseases may be more widespread and severe in minority populations and therefore may provide an important key for the study of periodontal disease progression by providing a subject population with a disproportionate level of periodontal disease activity. The aim of this application is to apply the methodologies developed by Forsyth to define and study a set of clinical, demographic, immunologic and microbiologic risk factors for periodontal disease progression in a sample of 80 Asiatic, 80 Black and 80 Hispanic subjects equally divided between periodontally healthy and diseased groups. Subjects will be followed longitudinally: at baseline, 2 months post-baseline, 6 and 12 months post- periodontal therapy. Clinical indices recorded at 6 sites per tooth at each monitoring visit will include pocket depth, attachment level, gingival erythema, suppuration, plaque, bleeding upon probing and pocket temperature. Subgingival plaque samples from up to 28 sites per subject will be analyzed for over 40 subgingival species using a checkerboard DNA probe hybridization technique. Serum IgG titers against 37 subgingival species will be determined using a checkerboard immunosorbant assay. Comparison of these data will relate specific clinical, immunologic, microbiologic and demographic variables with the risk of new attachment loss in minority populations and will be compared to results of a similarly monitored non-minority population at Forsyth. The results will permit an estimate of periodontal disease severity, prevalence, progression and response to therapy in three urban minority populations and aid in the formulation of strategies to control periodontal diseases in minorities.